1. Field of the Invention
The present invention relates to a rotary input device by which a click feeling can be obtained.
2. Description of the Related Art
In recent years, a rotary input device by which a click feeling can be obtained is used in various industrial fields. For example, an information input device for rotation detection is disclosed in Japanese Unexamined Patent Application Publication No. 2003-280799.
FIG. 24 is an exploded perspective view showing an information input device 100 disclosed in Japanese Unexamined Patent Application Publication No. 2003-280799. FIGS. 25A and 25B are perspective views showing a rotation detection magnetic body 152 of FIG. 24, FIG. 25A is a perspective view showing a positional relationship of a hall IC 136a with respect to a rotation detection magnetic body 152, and FIG. 25B is a perspective view showing a portion of the rotation detection magnetic body 152 in an enlarged manner.
A holding ring 164 and an operation dial 154 are in a state of being rotatably held on a base 120, and if the holding ring and the operation dial are pressed, the holding ring and the operation dial are mounted to turn a central tact switch 133 on. Moreover, in the operation dial 154, if where the center portion of the operation dial is separated vertically and horizontally is pressed from the upper portion, the operation dial acts on the tact switch 132 and turns the tact switch on.
A click feeling generating magnetic body 142 is configured of two arc pieces 144a and 144b, and two arc pieces are integrally held by one annular holding portion 146 and are positioned on one circumference. The arc pieces 144a and 144b are formed of a magnetic body, and thus, are magnetized to bear magnetism. The rotation detection magnetic body 152 is integrally mounted to the operation dial 154. An outer diameter of the rotation detection magnetic body 152 is larger than an outer diameter of the click feeling generating magnetic body 142, and similar to the arc pieces 144a and 144b, the rotation detection magnetic body is formed of a magnetic body, and thus, is magnetized to bear magnetism.
A magnetic field defined by magnetic poles of the rotation detection magnetic body 152 is detected by hall ICs 136a and 136b, and if the operation dial 154 is rotated, strength of the detected magnetic field is changed, and thus, it is possible to detect a rotation amount and a rotation direction of the operation dial 154.
The click feeling generating magnetic body 142 is positioned inside the rotation detection magnetic body 152 and magnetically interacts with the rotation detection magnetic body 152, and if the operation dial 154 is rotated, a click feeling is generated by the magnetic interaction. The rotation detection magnetic body 152 is formed in a doughnut shape, and as shown in FIG. 25A, N poles and S poles are alternately disposed with a constant pitch when viewed from the above. As shown in FIG. 25B, in a portion of the N pole when viewed from the above, the upper side becomes the N pole and the lower side becomes the S pole. Moreover, in a portion of the S pole when viewed from the above, the upper side becomes S pole and the lower side becomes N pole. This makes the rotation detection magnetic body 152 magnetize vertically for each range corresponding to the pitch. The click feeling generating magnetic body 142 is also magnetized by the similar method.
According to the magnetic interaction between the rotation detection magnetic body 152 and the click feeling generating magnetic body 142, the click feeling is generated for each disposition angle pitch of the sets of the N poles and the S poles. Accordingly, for example, it is possible to remove unevenness or variation in the click feeling generated due to dimensional errors or wear of the rotation detection magnetic body 152 or the click feeling generating magnetic body 142.
However, in the rotation detection magnetic body 152 and the click feeling generating magnetic body 142, the S poles and the N poles are alternately disposed in the circumferential direction, and for example, complicated magnetizing means in which the positions of the poles are slightly deviated and the poles are magnetized is required. Therefore, there is a problem that a cost according to the magnetization is increased. Moreover, when magnetic attraction is not strong, it is not possible to obtain an improved click feeling.